/Engine/Plugins/Online/OnlineServicesOSSAdapter/Source/Public/Online/AuthOSSAdapter.h
Retrieves a token appropriate for linking the service account with a service account of a different service type. On most platforms this will return an OpenId token. May return a cached token, but will handle refreshing if necessary.
virtual [TOnlineAsyncOpHandle](API\Plugins\OnlineServicesInterface\Online\TOnlineAsyncOpHandle)< [FAuthQueryExternalAuthToken](API\Plugins\OnlineServicesInterface\Online\FAuthQueryExternalAuthToken) > QueryExternalAuthToken ( [FAuthQueryExternalAuthToken::Params](API\Plugins\OnlineServicesInterface\Online\FAuthQueryExternalAuthToken\Params) && Params )